Rinse and soak lentils overnight. Drain.
In a medium pot, heat oil and add spice or curry powder, stirring constantly for half a minute or until they become aromatic. Don't let it get smokey. Add the onion and salt and cook it down, stirring occasionally for about 15 minutes. If adding shredded vegetables, do it now and cook for an additional five minutes. Set aside.
In a soup pot, cook the lentils in water to cover plus the tomatoes and coconut milk. Add water as necessary to make the soup to the desired thickness. Pink lentils cook fast, about 20 minutes. When almost soft, add the onion, spice and cooked vegetable mixture and simmer another 10 minutes or until lentils are cooked through.
Flavor balance with cider vinegar, salt and pepper.
Serve with a garnish of chopped parsley or cilantro.